ENMA 300 and ENME 382
Homework 1
Due: Friday, Feb. 4, 2011
1. Predict the type of bonding that holds the atoms/molecules together in the following solid
materials. Explain why you have made the prediction for each material. Where appropriate
include calcu

ENMA 300
Homework 8 Solutions
1a) The critical resolved shear stress for copper is 0.48 MPa (70 psi). Determine the minimum possible
yield strength for a single crystal of Cu pulled in tension.
In order to determine the minimum possible yield strength for

ENMA 300
Homework 1
Due: Sept. 9, 2010
Note: You should get in the habit of showing your work even if you can solve a problem in your
head. Reasoning is important and you need to show work to show your reasoning process.
1. Predict the type of bonding tha

Waqaas Ali
ENMA-300
Metallography
Metallography is basically the study of metals often through the methods of
microcopy. Metal surfaces and fractures are examined with the eye or with a magnifying
glass or metallurgical or binocular microscope at magnific

HW 4
ENME 382
4.3 Below, molecular weight data for a polytetrafluoroethylene material are tabulated. Compute (a) the numberaverage molecular weight, (b) the weight-average molecular weight, and (c) the degree of polymerization.
Molecular Weight
Range (g/m

Department of Materials Science and Engineering
University of Maryland
College Park, MD
ENMA 300: Problem Set #3
SOLUTIONS
1. Lattices (2D and 3D)
Identify the lattices and the unit cell in the following images:
(a)
[Source: M. C. Escher]
The white outlin

ENMA 300
Homework 11
Due: Dec 7, 2010
1. This is a combination of problems 10.5 and 10.8 because as a combination they provide
important practice for interpreting phase diagrams. Remember that while book gives formulas
for converting weight percent to mol

ENMA 300: Problem Set #10
1. Under what conditions can Ficks first law be used to solve diffusion problems?
It can be used to solve diffusion problems provided the concentration gradient does not
change over time.
2. Silica can be either a crystalline sol

HOMEWORK # 9
Name _
ENMA 300
DUE: Thursday, November 11, 2010
1.
A through-thickness crack of length 0.5 mm grows from a 10 mm diameter hole in a 25
mm thick plate of hardened Al that has the properties listed below. The crack is subjected
to a nominal st

ENMA 300
Homework 8
1a) The critical resolved shear stress for copper is 0.48 MPa (70 psi). Determine the minimum possible
yield strength for a single crystal of Cu pulled in tension.
bi) A single crystal of a metal that has the BCC crystal structure is o

Prof. Rabin: [email protected]; X53382; CHE 1110B
ENMA 300: Problem Set #7
Date Posted: Thr 10/21/10
Time Due: Thr 10/28/10 5PM.
Dislocations
1. A metal crystal has a Burgers vector of length 0.272nm. If the lattice parameter a is 0.314, is
the metal crystal s

ENMA 300: Solutions Set #7
Dislocations
1. A metal crystal has a Burgers vector of length 0.272nm. If the lattice parameter a is 0.314, is
the metal crystal structure FCC or BCC?
The Burgers vector is (a/2)*[110] in FCC structures and (a/2)*[111] in BCC s

Department of Materials Science and Engineering
University of Maryland
College Park, MD
ENMA 300: Problem Set #3
1. Lattices (2D and 3D)
Identify the lattices and the unit cell in the following images:
(a)
(b)
[Source: M. C. Escher]
[Source: M.C. Escher]

Homework # 6
5.5: (a) Atomic radius, crystal structure, electronegativity, and the most common valence are tabulated
below, for several elements. Which of these elements would you expect to form a substitutional solid
solution with nickel having complete

Homework # 6
5.5: (a) Atomic radius, crystal structure, electronegativity, and the most common valence are tabulated
below, for several elements. Which of these elements would you expect to form a substitutional solid
solution with nickel having complete

HW 5
ENMA 300
5.1
5.12 Some hypothetical alloy is composed of 25 wt% of metal A and 75 wt% of metal B. If the densities of metals A
and B are 6.17 and 8.00 g/cm3, respectively, whereas their respective atomic weights are 171.3 and 162.0 g/mol,
determine w

HW 5
ENMA 300
5.1 Calculate the fraction of atom sites that are vacant for copper at its melting temperature of 1084degC. Assume
an energy for vacancy formation of 0.90 eV/atom.
5.12 Some hypothetical alloy is composed of 25 wt% of metal A and 75 wt% of m

HOMEWORK # 9
Name _
ENMA 300
DUE: Thursday, November 11, 2010
1. A through-thickness crack of length 0.5 mm grows from a 10 mm diameter hole
in a 25 mm thick plate of hardened Al that has the properties listed below. The
crack is subjected to a nominal st

Homework #2
ENMA 300
Due Tuesday, September 21, 2010
Name _
Questions for Grading:
1. Calculate the ionic radius ratio for MgO and determine from it the coordination number
for the Mg. Using the ionic radius ratio and the ionic charge (stoichiometry), pre

ENMA 300
Homework 11
Due: Noon Dec 10, 2010
1. For each of the following alloys: i) Cite the phases that are present and the phase
compositions for each phases and ii) determine the relative amounts (in terms of mass fractions)
of the phases for the alloy

ENMA 300 ENME 382
Homework 4
Due: Thursday, October 5, 2010
1. Callister 4.3
Below, molecular weight data for a polytetrafluoroethylene material are tabulated. Compute (a) the
number-average molecular weight, (b) the weight-average molecular weight, and (

ENMA 300
Homework 1
Due: Sept. 14, 2010
1. Predict the type of bonding that holds the atoms/molecules together in the following solid
materials. Explain why you have made the prediction for each material. Where appropriate
include calculations.
CaO
CdS
Fe

ENMA300: Homework #10
Date Posted: Tue 11/23/2010
Time Due: Tue 11/30/2010 3 PM.
1. Under what conditions can Ficks first law be used to solve diffusion problems?
2. Silica can be either a crystalline solid or a glass at room temperature. Is diffusion fas

Answer Key_
QUIZ # 4
ENMA 300
December 8, 2010
Name _
The following THREE questions refer to the phase diagram between METAL A and
METAL B in FIGURE 1.
1. Please identify in the table below, the phases present in each of the numbered
regions of the phase

Answer Key_
FINAL EXAM
Name _
ENME 382
Engineering Materials and Manufacturing Processes
May 19, 2008
There are 15 questions on the exam worth 150 pts. You have 120 minutes. Please place
the answers in the spaces provided. Please sign the honor pledge on

UniversityofMarylandHonorPledge:
IpledgeonmyhonorthatIhavenotgivenorreceivedanyunauthorizedassistanceonthisexam.
Mynameandsignatureonpage1attestthatIhavereadandagreewiththeabovestatement.
Printed Name:_ Signature: _
Instructions:
1. SHOW YOUR WORK (includ

ENME 382
Engrg Matls and Mfrg Processes
March 10, 2004
Name _
There are 12 questions. You have 60 minutes for the exam. Place the answer in
the space provided. Show all your work for partial credit.
1. Match the defect with the definition (10 pts)
_
Schot

University of Maryland Honor Pledge:
I pledge on my honor that I have not given or received any unauthorized assistance on this exam.
My name and signature on page 1 attest that I have read and agree with the a